Gerand K-1250-6 Fire Pump Flow Test Meter – FM Approved Venturi-type meter provides an accurate and economical way to obtain flow measurements in HVAC, industrial, municipal and mining systems. Flow losses are minimized by this design. A flow loss equal to as little as 10% of the differential pressure is typical. Grooved end design allows fast, easy installation with standard Victaulic couplings. All sizes have a minimum straight pipe requirement of five diameters upstream and two downstream.